Febrile convulsions are the most common childhood seizure disorder, affecting 2-5% of children by age five, about 100,000 new cases per year. Many receive expensive and invasive diagnosis workups. A large proportion are also placed on anticonvulsant medication. Approximately 30% of those who experience a febrile convulsion will have one or more recurrences. Most studies have focused on the long-term consequences of febrile convulsions; however, very little is known about the immediate illnesses associated with febrile convulsions or other antecedents of febrile convulsions. In addition, few risk factors for recurrent febrile convulsions have been identified. The primary aims of the proposed study are to identify (1) immediate precipitants of febrile convulsions. (2) antecedent risk factors for febrile convulsions, and (3) risk factors for recurrent febrile convulsions. Where possible, the study will also examine: (4) correlates of known risk factors for subsequent epilepsy in an effort to help clarify the association between febrile convulsions and epilepsy, (5) an explanation for the excess sale risk among children with first febrile convulsions, and (6) characteristics of the convulsion and of the child's condition indicative of intracranial infections. The proposal is for a case-control study of first febrile convulsions and a one-year follow-up of cases for recurrent febrile convulsions. Cases and controls will be identified over a three- year period from among children seeking care at three Bronx hospitals. Information will be obtained through medical record review and interviews with the children's parents. The information obtained will (1) identify immediate precipitants of febrile convulsions as well as antecedent risk factors thus furthering our understanding of this very common childhood disorder, (2) identify some potentially preventable factors associated with febrile convulsions, and (3) identify predictors of recurrent febrile convulsions allowing better targeting of anticonvulsant prophylaxis. Results from this study also may help clarify the consistent associations between febrile convulsions and later epilepsy and indirectly provide some insights into the etiology of epilepsy.